Diacetyl is a commonly used food additive made to give a buttery flavor to breads, cookies, candy and other goods. For decades, the chemical has been classified as “GRAS” (generally recognized as safe) by the US Food and Drug Administration. But for workers exposed to the chemical in food production factories, there is compelling scientific evidence that exposure to diacetyl is associated with a range of respiratory conditions, including the bronchiolitis obliterans.

The most publicized cases of this occupational illness have been among workers in microwave popcorn packing plants. (SKAPP has been following this issue for several years; read a full case study on diacetyl on our website.) In September of 2006, SKAPP petitioned the FDA to revoke diacetyl’s GRAS status. In a reply dated March 6, 2007, the Director of FDA’s Office of Food Additive Safety, said

“we have not reached a decision on your petition within the 180 days of the filing of the petition because of the limited availability of resources and other agency priorities.”

FDA’s Center for Food Safety and Applied Nutrition administers a program to conduct ongoing toxicological reviews of the thousands of substances added to food and maintains a database called “Everything Added to Food in the U.S.” (EAFUS). Their records show that “full toxicological information on diacetyl has been sought.” Let’s hope their toxicological review includes potential adverse health effects for workers exposed to the food flavoring fumes.